Have you ever wondered what constitutes a web document that you click on or request from search engines like Google or Yahoo?

Any given document you request is delivered to you by an HTTP reply composed of two parts: header and body. The meta information is contained in the header and the actual document you view is contained the body on the other hand.

Content-type is indeed a very important HTTP header because it tells the MIME type of a web document. The MIME type is the one that tells the user agent what kind of content it is going to get.

A Content-Type header for an HTML document is something like this one:
Content-Type: text/html; charset=utf-8
In case of XHTML document, the content-type will appear something similar to this:
Content-Type: application/xhtml+xml

The reason why MIME type is so significant is that it tells the browser how it should handle the web document. For an XML MIME type, the tag’s xmlns attribute is what specifies a document as containing XHTML. The doctype declaration has nothing to do with this matter, except when it comes to validating the markup.

You should, at this moment, remember that Internet Explorer doesn’t support the MIME type application/xhtml+xml. Although it supports application/xml and text/xml, it’ll treat the document as generic XML rather than XHTML. This matter is the exact reason why many designers and authors serve their XHTML markup as text/html. Nevertheless, only a handful of authors realize that this causes browsers to handle their pages as HTML, rather than XHTML.

MIME types as well as many other concepts should always be taken in their proper perspective. Sufficient attention to these matters will lend you so many benefits that you will always find more interesting too.

Having said all these, it is suggested that you always try your best to enrich your knowledge on basic and advanced stuff about CSS in particular and web designing in general. With many creative authors budding from the four corners of the web design realm you are sure to find stiff competition anywhere. And one very sure way to stay competitive is learn, learn and learn some more.

Tags: MIME Types